The value of at the middle of the strip can he deduced from 
equation 84 by substituting N for X/B, and assuming that Y/B = 1.25, 
we get: 
2 -y 4 
jU^H = (1 ** 35 -1 * 2 5 n +0.375n 2 -0.625n3+o.o15625N 1 *). (85) 
at the end of the strip (N bridged models) will then be given as 
(h.35 -1.25N +0.375n 2 -0.0625n3+0.015625n 1 *)=, i 86 ) 
In other words, the maximum expected mean square value of the residual 
errors in elevation at the end of the bridged distance could be given 
by: 
/^ H = Z ^° f Z ~(h.35 -1.25N ^0.375N 2 -0.0625n3+0.015625N^)^. (87) 
Efforts have been made to simplify equation (87), and it was 
found that: 
1. for the cases where the number of bridged models is FIVE or less, 
(lj.528 -l.llliN +0.288N 2 ). (88) 
2. for the cases where the number of bridged models is SIX OR MORE, 
M- H (2*3oU -0.506N +0.250N 2 ). 
^aH 
(89)